Key Physicochemical Determinants in the Antimicrobial Peptide RiLK1 Promote Amphipathic Structures.

Antimicrobial peptides (AMPs) represent a skilled class of new antibiotics, due to their broad range of activity, rapid killing, and low bacterial resistance. Many efforts have been made to discover AMPs with improved performances, i.e., high antimicrobial activity, low cytotoxicity against human cells, stability against proteolytic degradation, and low costs of production. In the design of new AMPs, several physicochemical features, such as hydrophobicity, net positive charge, propensity to assume amphipathic conformation, and self-assembling properties, must be considered. Starting from the sequence of the dodecapeptide 1018-K6, we designed a new 10-aminoacid peptide, namely RiLK1, which is highly effective against both fungi and Gram-positive and -negative bacteria at low micromolar concentrations without causing human cell cytotoxicity. In order to find the structural reasons explaining the improved performance of RiLK1 versus 1018-K6, a comparative analysis of the two peptides was carried out with a combination of CD, NMR, and fluorescence spectroscopies, while their self-assembling properties were analyzed by optical and atomic force microscopies. Interestingly, the different spectroscopic and microscopic profiles exhibited by the two peptides, including the propensity of RiLK1 to adopt helix arrangements in contrast to 1018-K6, could explain the improved bactericidal, antifungal, and anti-biofilm activities shown by the new peptide against a panel of food pathogens.

A Safe and Multitasking Antimicrobial Decapeptide: The Road from De Novo Design to Structural and Functional Characterization.

Antimicrobial peptides (AMPs) are excellent candidates to fight multi-resistant pathogens worldwide and are considered promising bio-preservatives to control microbial spoilage through food processing. To date, designing de novo AMPs with high therapeutic indexes, low-cost synthesis, high resistance, and bioavailability, remains a challenge. In this study, a novel decapeptide, named RiLK1, was rationally designed starting from the sequence of the previously characterized AMP 1018-K6, with the aim of developing short peptides, and promoting higher selectivity over mammalian cells, antibacterial activity, and structural resistance under different salt, pH, and temperature conditions. Interestingly, RiLK1 displayed a broad-spectrum of bactericidal activity against Gram-positive and Gram-negative bacteria, including multidrug resistant clinical isolates of Salmonella species, with Minimal Bactericidal Concentration (MBC) values in low micromolar range, and it was effective even against two fungal pathogens with no evidence of cytotoxicity on human keratinocytes and fibroblasts. Moreover, RiLK1-activated polypropylene films were revealed to efficiently prevent the growth of microbial spoilage, possibly improving the shelf life of fresh food products. These results suggested that de novo designed peptide RiLK1 could be the first candidate for the development of a promising class of decameric and multitask antimicrobial agents to overcome drug-resistance phenomena.

Functionalized Polymeric Materials with Bio-Derived Antimicrobial Peptides for "Active" Packaging.

Food packaging is not only a simple protective barrier, but a real "active" component, which is expected to preserve food quality, safety and shelf-life. Therefore, the materials used for packaging production should show peculiar features and properties. Specifically, antimicrobial packaging has recently gained great attention with respect to both social and economic impacts. In this paper, the results obtained by using a polymer material functionalized by a small synthetic peptide as "active" packaging are reported. The surface of Polyethylene Terephthalate (PET), one of the most commonly used plastic materials in food packaging, was plasma-activated and covalently bio-conjugated to a bactenecin-derivative peptide named 1018K6, previously characterized in terms of antimicrobial and antibiofilm activities. The immobilization of the peptide occurred at a high yield and no release was observed under different environmental conditions. Moreover, preliminary data clearly demonstrated that the "active" packaging was able to significantly reduce the total bacterial count together with yeast and mold spoilage in food-dairy products. Finally, the functionalized-PET polymer showed stronger efficiency in inhibiting biofilm growth, using a Listeria monocytogenes strain isolated from food products. The use of these "active" materials would greatly decrease the risk of pathogen development and increase the shelf-life in the food industry, showing a real potential against a panel of microorganisms upon exposure to fresh and stored products, high chemical stability and re-use possibility.

Small Synthetic Peptides Bioconjugated to Hybrid Gold Nanoparticles Destroy Potentially Deadly Bacteria at Submicromolar Concentrations.

Synthetic antibacterial peptides are advanced weapons that scientists design and produce to confront current threats of harmful and mortal pathogens, which could affect humans in everyday life. Recently, many small amino acid sequences, greatly efficient in their antibacterial action, have been reported in the literature. To date, only a few synthetic peptides, acting at micromolar or even tenths of micromolar concentrations, are on the market as commercial products, mainly because of their high cost of production. In this context, materials science can provide fundamental help by engineering small synthetic peptides, powered by hybrid gold nanoparticles, which have been found to strongly enhance antimicrobial activity against bacterial infections. Submicromolar concentrations of the 1018K6 peptide, bioconjugated to hybrid polymer-gold nanoparticles, kill almost 100% of pathogen bacteria, such as Listeria and Salmonella genera, paving the way for economically sustainable commercial products based on this synthetic nanocomplex.

Unusual Antioxidant Properties of 26S Proteasome Isolated from Cold-Adapted Organisms.

The oxidative challenge represents an important factor affecting the adaptive strategies in Antarctic fish, but their impact on the protein degradation machinery still remains unclear. The previous analysis of the first 26S proteasome from the Antarctic red-blooded fish Trematomus bernacchii, evidenced improved antioxidant functions necessary to counteract the environmental pro-oxidant conditions. The purpose of this work was to carry out a study on 26S proteasomes from the temperate red-blooded Dicenthrarcus labrax and the icefish Chionodraco hamatus in comparison with the isoform already described from T. bernacchii, to better elucidate the cold-adapted physiological functions of this complex. Therefore, the 26S isoforms were isolated and the complementary DNAs (cDNAs) codifying the catalytic subunits were cloned. The biochemical characterization of Antarctic 26S proteasomes revealed their significantly higher structural stability and resistance to H2O2 with respect to that of the temperate counterpart, as also suggested by a comparative modeling analysis of the catalytic subunits. Moreover, in contrast to that observed in T. bernacchii, the 26S systems from C. hamatus and D. labrax were incapable to hydrolyze oxidized proteins in a ubiquitin-independent manner. Therefore, the 'uncommon' properties displayed by the Antarctic 26S proteasomes can mirror the impact exercised by evolutionary pressure in response to richly oxygenated environments.

APEH Inhibition Affects Osteosarcoma Cell Viability via Downregulation of the Proteasome.

The proteasome is a multienzymatic complex that controls the half-life of the majority of intracellular proteins, including those involved in apoptosis and cell-cycle progression. Recently, proteasome inhibition has been shown to be an effective anticancer strategy, although its downregulation is often accompanied by severe undesired side effects. We previously reported that the inhibition of acylpeptide hydrolase (APEH) by the peptide SsCEI 4 can significantly affect the proteasome activity in A375 melanoma or Caco-2 adenocarcinoma cell lines, thus shedding new light on therapeutic strategies based on downstream regulation of proteasome functions. In this work, we investigated the functional correlation between APEH and proteasome in a panel of cancer cell lines, and evaluated the cell proliferation upon SsCEI 4-treatments. Results revealed that SsCEI 4 triggered a proliferative arrest specifically in osteosarcoma U2OS cells via downregulation of the APEH-proteasome system, with the accumulation of the typical hallmarks of proteasome: NF-κB, p21(Waf1), and polyubiquitinylated proteins. We found that the SsCEI 4 anti-proliferative effect involved a senescence-like growth arrest without noticeable cytotoxicity. These findings represent an important step toward understanding the mechanism(s) underlying the APEH-mediated downregulation of proteasome in order to design new molecules able to efficiently regulate the proteasome system for alternative therapeutic strategies.

A new pepstatin-insensitive thermopsin-like protease overproduced in peptide-rich cultures of Sulfolobus solfataricus.

In this study, we gain insight into the extracellular proteolytic system of Sulfolobus solfataricus grown on proteinaceous substrates, providing further evidence that acidic proteases were specifically produced in response to peptide-rich media. The main proteolytic component was the previously isolated SsMTP (Sulfolobus solfataricus multi-domain thermopsin-like protease), while the less abundant (named SsMTP-1) one was purified, characterized and identified as the sso1175 gene-product. The protein revealed a multi-domain organization shared with the cognate SsMTP with a catalytic domain followed by several tandemly-repeated motifs. Moreover, both enzymes were found spread across the Crenarchaeota phylum and belonging to the thermopsin family, although segregated into diverse phylogenetic clusters. SsMTP-1 showed a 75-kDa molecular mass and was stable in the temperature range 50-90 °C, with optimal activity at 70 °C and pH 2.0. Serine, metallo and aspartic protease inhibitors did not affect the enzyme activity, designating SsMTP-1 as a new member of the pepstatin-insensitive aspartic protease family. The peptide-bond-specificity of SsMTP-1 in the cleavage of the oxidized insulin B chain was uncommon amongst thermopsins, suggesting that it could play a distinct, but cooperative role in the protein degradation machinery. Interestingly, predictions of the transmembrane protein topology of SsMTP and SsMTP-1 strongly suggest a possible contribution in signal-transduction pathways.

Systematic review for the development of a core outcome set for monofocal intraocular lenses for cataract surgery.

Introduction: The aim of the study was to define a core outcome set (COS) to be measured following cataract surgery for the postoperative evaluation of monofocal intraocular lenses (IOLs). Compared to current COSs, the present work provides updates considering the advances in the technology due to the development of new generation monofocal IOLs, which are characterized by a safety profile comparable to standard monofocal IOLs but with an extended range of intermediate vision. Methods: Healthcare professionals (ophthalmologist surgeons) and patients were involved in the selection of outcomes to be included in the COS, starting from a list of indicators retrieved from a systematic literature search. The search considered observational studies with both a retrospective or prospective design, case studies and classic randomized controlled trials (RCTs). A mixed methodology integrating a Delphi-driven and an expert panel approach was adopted to reach an agreement among clinicians, while patients were involved in the completion of a questionnaire. Results: The final COS included 15 outcomes. Eleven outcomes, all clinical, were considered for inclusion after a joint discussion among ophthalmologists; seven outcomes were linked to visual acuity, while the remaining to contrast sensitivity, refractive errors, aberrations and adverse events. Measurement metrics, method of aggregation and measurement time point of these outcomes were specified. The most important aspects for the patients were (1) quality of life after cataract surgery, (2) the capacity to perform activities requiring good near vision (e.g., reading), (3) spectacle independence, and (4) safety of movements without fear of getting hurt or falling (intermediate vision). Discussion: In a context with limited healthcare resources, it is important to optimize their use considering also the preferences of end-users, namely patients. The proposed COS, developed involving both ophthalmologists and patients, provides an instrument for the postoperative evaluation of different technologies in the context of monofocal IOLs, which can be used not only in clinical trials but also in clinical practice to increase the body of real-world evidence.

Surface-exposed glycoproteins of hyperthermophilic Sulfolobus solfataricus P2 show a common N-glycosylation profile.

Cell surface proteins of hyperthermophilic Archaea actively participate in intercellular communication, cellular uptake, and energy conversion to sustain survival strategies in extreme habitats. Surface (S)-layer glycoproteins, the major component of the S-layers in many archaeal species and the best-characterized prokaryotic glycoproteins, were shown to have a large structural diversity in their glycan compositions. In spite of this, knowledge on glycosylation of proteins other than S-layer proteins in Archaea is quite limited. Here, the N-glycosylation pattern of cell-surface-exposed proteins of Sulfolobus solfataricus P2 were analyzed by lectin affinity purification, HPAEC-PAD, and multiple mass spectrometry-based techniques. Detailed analysis of SSO1273, one of the most abundant ABC transporters present in the cell surface fraction of S. solfataricus, revealed a novel glycan structure composed of a branched sulfated heptasaccharide, Hex4(GlcNAc)2 plus sulfoquinovose where Hex is d-mannose and d-glucose. Having one monosaccharide unit more than the glycan of the S-layer glycoprotein of S. acidocaldarius, this is the most complex archaeal glycan structure known today. SSO1273 protein is heavily glycosylated and all 20 theoretical N-X-S/T (where X is any amino acid except proline) consensus sequence sites were confirmed. Remarkably, we show that several other proteins in the surface fraction of S. solfataricus are N-glycosylated by the same sulfated oligosaccharide and we identified 56 N-glycosylation sites in this subproteome.

A new versatile peroxidase with extremophilic traits over-produced in MicroTom cell cultures.

Peroxidases are widespread key antioxidant enzymes that catalyse the oxidation of electron donor substrates in parallel with the decomposition of H2O2. In this work, a novel tomato peroxidase, named SAAP2, was isolated from MicroTom cell cultures, purified, and characterised. The enzyme was identified with 64% sequence coverage as the leprx21 gene product (suberization-associated anionic peroxidase 2-like) from Solanum lycopersicum, 334 amino acids long. Compared to other plant peroxidases, SAAP2 was more active at elevated temperatures, with the optimal temperature and pH at 90 °C and 5.0, respectively. Furthermore, the enzyme retained more than 80% of its maximal activity over the range of 70-80 °C and the presence of NaCl (1.0-4.5 M). It also exhibited broad pH versatility (65% relative activity over the pH range 2.0-7.0), acid-tolerance (80% residual activity after 22 h at pH 2.0-7.0), high thermostability (50% residual activity after 2 h at 80 °C) and proteolytic resistance. SAAP2 exhibited exceptional resistance under thermo-acidic conditions compared to the horseradish peroxidase benchmark, suggesting that it may find potential applications as a supplement or anti-pollution agent in the food industry.

Antimicrobial activity, membrane interaction and structural features of short arginine-rich antimicrobial peptides.

Antimicrobial activity of many AMPs can be improved by lysine-to-arginine substitution due to a more favourable interaction of arginine guanidinium moiety with bacterial membranes. In a previous work, the structural and functional characterization of an amphipathic antimicrobial peptide named RiLK1, including lysine and arginine as the positively charged amino acids in its sequence, was reported. Specifically, RiLK1 retained its ß-sheet structure under a wide range of environmental conditions (temperature, pH, and ionic strength), and exhibited bactericidal activity against Gram-positive and Gram-negative bacteria and fungal pathogens with no evidence of toxicity on mammalian cells. To further elucidate the influence of a lysine-to-arginine replacement on RiLK1 conformational properties, antimicrobial activity and peptide-liposome interaction, a new RiLK1-derivative, named RiLK3, in which the lysine is replaced with an arginine residue, was projected and characterised in comparison with its parental compound. The results evidenced that lysine-to-arginine mutation not only did not assure an improvement in the antimicrobial potency of RiLK1 in terms of bactericidal, virucidal and fungicidal activities, but rather it was completely abolished against the hepatitis A virus. Therefore, RiLK1 exhibited a wide range of antimicrobial activity like other cationic peptides, although the exact mechanisms of action are not completely understood. Moreover, tryptophan fluorescence measurements confirmed that RiLK3 bound to negatively charged lipid vesicles with an affinity lower than that of RiLK1, although no substantial differences from the structural and self-assembled point of view were evidenced. Therefore, our findings imply that antimicrobial efficacy and selectivity are affected by several complex and interrelated factors related to substitution of lysine with arginine, such as their relative proportion and position. In this context, this study could provide a better rationalisation for the optimization of antimicrobial peptide sequences, paving the way for the development of novel AMPs with broad applications.

An Active Peptide-Based Packaging System to Improve the Freshness and Safety of Fish Products: A Case Study.

Fresh fish are highly perishable, owing mainly to their moisture content, high amount of free amino acids and polyunsaturated fatty acids. Microorganisms and chemical reactions cause the spoilage, leading to loss in quality, human health risks and a market value reduction. Therefore, the fishing industry has always been willing to explore new technologies to increase quality and safety of fish products through a decrease of the microbiological and biochemical damage. In this context, antimicrobial active packaging is one such promising solution to meet consumer demands. The main objective of this study was to evaluate the effects of an active polypropylene-based packaging functionalized with the antimicrobial peptide 1018K6 on microbial growth, physicochemical properties and the sensory attributes of raw salmon fillets. The results showed that application of 1018K6-polypropylene strongly inhibited the microbial growth of both pathogenic and specific spoilage organisms (SSOs) on fish fillets after 7 days. Moreover, salmon also kept its freshness as per volatile chemical spoilage indices (CSIs) during storage. Similar results were obtained on hamburgers of Sarda sarda performing the same analyses. This work provides further evidence that 1018K6-polymers have good potential as antimicrobial packaging for application in the food market to enhance quality and preserve the sensorial properties of fish products.

Direct-acting Antivirals Inducing HCV-RNA Sustained Suppression Improve Xerophthalmia in HCV-infected Patients.

BACKGROUND: Hepatitis C Virus (HCV) infection represents a global problem, and it is related to both hepatic and extra-hepatic manifestations (e.g., xerophthalmia). New direct-acting antivirals (DAAs), IFN-free treatments, are commonly used to manage HCV infection. However, the impact of new DAAs on dry eyes (xerophthalmia) is lacking. In this study, we evaluated its incidence in HCV patients and the effect of DAAs on this manifestation. METHODS: We performed an observational open-label non-randomized study in HCV patients from 01 April 2018 to 01 June 2020. RESULTS: Patients who satisfied the inclusion criteria underwent clinical and laboratory evaluation, Schirmer's test, and Break-up time test. Enrolled patients were divided in two groups: Group 1: HCV patients with xerophthalmia: 24 patients (16 male and 8 female), HCV-RNA 2,685,813 ± 1,145,698; Group 2: HCV patients without xerophthalmia: 35 patients (19 male and 16 female), HCV-RNA 2,614,757 ± 2,820,433. The follow-ups (3 and 6 months after the enrollment) documented an improvement in both eyes' manifestations and HCV-infection (HCV-RNA undetected). CONCLUSION: In conclusion, in this study, we reported that xerophthalmia could appear in HCV patients, and DAAs treatment reduces this manifestation without the development of adverse drug reactions.

Comparison of corneal densitometry between big-bubble and visco-bubble deep anterior lamellar keratoplasty.

AIMS: To evaluate deep corneal densitometry and visual outcomes after big-bubble (BB-DALK) and visco-bubble (VB-DALK) deep anterior lamellar keratoplasty performed in patients with keratoconus. METHODS: Prospective comparative study of 50 advanced keratoconic patients who underwent DALK surgery; 25 eyes (group I) were completed with BB-DALK and 25 eyes (group II) with VB-DALK after the failure of pneumatic dissection. Best spectacle-corrected visual acuity (BSCVA), corneal tomographic parameters and endothelial cell count were recorded 1, 3, 6, 12 and 24 months after surgery. Densitometric analysis of the deep corneal interface was obtained using Scheimpflug tomography at each visit; values recorded were compared between the two groups and statistically analysed. RESULTS: BSCVA was significantly better in the BB-DALK group than the VB-DALK group (0.39±0.29 vs 0.65±0.23 logarithm of the minimum angle of resolution, respectively) for the first 3 months; and in the same time period, densitometry was significantly higher in the VB-DALK group than those recorded in the BB-DALK group (23.97±5.34 vs 17.13±4.44 grayscale units). However, densitometric values and visual acuity did not differ significantly in the two groups at 1 year. No statistically significant difference for the other variables analysed at any time frame was found. CONCLUSION: The use of viscoelastic substance in the VB-DALK technique may induce modification of interface stromal reflectivity resulting in reduced visual acuity up to 3 months postoperatively. However, this initial negative effect on the interface quality does not affect the long-term visual outcome, with densitometric values and visual outcomes similar in the two groups from 6 months postoperatively.

The Bactericidal Activity of Protein Extracts from Loranthus europaeus Berries: A Natural Resource of Bioactive Compounds.

Loranthus europaeus is a well-known and important medicinal plant, with a long history of traditional medicine use. Several studies showed that it contains many bioactive compounds with a wide range of pharmacological effects. In light of these past researches, L. europaeus were chosen to consider its potential antimicrobial action. To this aim, different protocols were performed to selectively extract protein compounds, from L. europaeus yellow fruits, and evaluate the antimicrobial activity against four phytopathogenic fungi (Aspergillus niger, Alternaria spp., Penicillium spp., Botritis cinereus) and a number of foodborne bacterial pathogens (Listeria monocytogenes, Staphylococcus aureus strains, Salmonella Typhimurium and Escherichia coli) by using serial dilutions and colony formation assays. Results evidenced no antifungal activity but a notable bactericidal efficiency of a crude protein extract against two foodborne pathogens, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values between 0.2 and 0.5 mg/mL, being S. aureus strains the most susceptible bacteria. Moreover, a strong bactericidal activity against S. aureus M7 was observed by two partially purified protein fractions of about 600 and 60 kDa molecular mass in native conditions. Therefore, these plant protein extracts could be used as natural alternative preventives to control food poisoning diseases and preserve foodstuff avoiding health hazards of chemically antimicrobial applications.

Extending the Shelf-Life of Meat and Dairy Products via PET-Modified Packaging Activated With the Antimicrobial Peptide MTP1.

Fresh products are characterized by reduced shelf-life because they are an excellent growth medium for a lot of microorganisms. Therefore, the microbial spoilage causing significant food supply losses has become an enormous economic and ethical problem worldwide. The antimicrobial packaging is offering a viable solution to tackle this economic and safety issue by extending the shelf-life and improving the quality and safety of fresh products. The goal of this study was to investigate the effects of a food contact surface of polyethylene terephthalate (PET) functionalized with the previously characterized antimicrobial peptide mitochondrial-targeted peptide 1 (MTP1), in reducing the microbial population related to spoilage and in providing the shelf-life stability of different types of fresh foods such as ricotta cheese and buffalo meat. Modified polymers were characterized concerning the procedure of plasma-activation by water contact angle measurements and Fourier transform infrared spectroscopy measurements in attenuated total reflection mode (ATR-FTIR). Results showed that the MTP1-PETs provided a strong antimicrobial effect for spoilage microorganisms with no cytotoxicity on a human colon cancer cell line. Finally, the activated polymers revealed high storage stability and good reusability. This study provided valuable information to develop alternative antimicrobial packaging for enhancing and extending the microbial quality and safety of perishable foods during storage.

The extraordinary resistance to UV radiations of a manganese superoxide dismutase of Deinococcus radiodurans offers promising potentialities in skin care applications.

An overproduction of free radicals or reactive oxygen species, often due to environmental factors, can alter the DNA structure and irreversibly modify proteins and lipids in the living cells. The superoxide anion (O2-) is one of the strongest oxidant molecules produced under oxidative stress conditions but it can be neutralized by the action of the enzymes SuperOxide Dismutases (SODs). In all the human tissues, SODs are essential for the prevention of serious diseases and the protection against oxidative stress damages. In the dermo-cosmetic sector, SODs have found promising applications, but their use is limited due to the loss of activity following the addition of the enzyme in the skin care formulas and the exposure of the skin to UV radiations and heat. Extremophile organisms, which proliferate in extreme physical and/or geochemical conditions, represent a potential source of stable SOD enzymes, able to function even in harsh conditions of high temperature, acid pH and long UV exposures. In the present study we investigated on a Mn-SOD deriving from the extremophilic bacterium Deinococcus radiodurans and, after its expression in E.coli, the Mn-SOD was characterized in terms of chemical and physical properties. Its extraordinary features in terms of UV resistance prompted us to investigate further about its potential applications in the dermo-cosmetic sector. It was expressed in Solanum lycopersicum (tomato) cell cultures with the main goal of developing a new ingredient, capable of keeping its ROS neutralizing activity once exposed to UV radiations and even when added to skin care formulas.

Bactericidal and antibiofilm activity of bactenecin-derivative peptides against the food-pathogen Listeria monocytogenes: New perspectives for food processing industry.

Antimicrobial peptides have received great attention for their potential benefits to extend the shelf-life of food-products. Innate defense regulator peptide-1018 (IDR-1018) represents a promising candidate for such applications, due to its broad-spectrum antimicrobial activity, although food-isolated pathogens have been poorly investigated. Herein, we describe the design and the structural-functional characterization of a new 1018-derivative peptide named 1018-K6, in which the alanine in position 6 was replaced with a lysine. Spectroscopic analysis revealed a noticeable switch from ß-sheet to helical conformations of 1018-K6 respect to IDR-1018, with a faster folding kinetic and increased structural stability. Moreover, 1018-K6 evidenced a significant antibiofilm/bactericidal efficiency specifically against Listeria monocytogenes isolates from food-products and food-processing environments, belonging to serotype 4b involved in the majority of human-listeriosis cases, with EC50 values two- five-fold lower than those measured for IDR-1018. Therefore, a single amino-acid substitution in IDR-1018 sequence produced severe changes in peptide conformation and antimicrobial performances.

Hemoglobin structure/function and globin-gene evolution in the Arctic fish Liparis tunicatus.

The importance of the Arctic, in contributing to the knowledge of the overall ensemble of adaptive processes influencing the evolution of marine organisms, calls for investigations on molecular adaptations in Arctic fish. Unlike the vast majority of Antarctic Notothenioidei, several Arctic species display high hemoglobin multiplicity. The blood of four species, the spotted wolffish of the family Anarhichadidae and three Gadidae, contains three functionally distinct major components. Similar to many Antarctic notothenioids, Arctic Liparis tunicatus (suborder Cottoidei, family Liparidae) has one major hemoglobin (Hb 1) accompanied by a minor component (Hb 2). This paper reports the structural and functional characterisation of Hb 1 of L. tunicatus. This hemoglobin shows low oxygen affinity, and pronounced Bohr and Root effects. The amino-acid sequence of the beta chain displays an unusual substitution in NA2 (beta2) at the phosphate-binding site, and the replacement of Val E11 (beta67) with Ile. Similar to some Antarctic fish Hbs, electron paramagnetic resonance spectra reveal the formation of a ferric penta-coordinated species even at physiological pH. The amino-acid sequences have also been used to gain insight into the evolutionary history of globins of polar fish. L. tunicatus globins appear close to the notothenioid clades as predicted by teleostean phylogenies. Close phylogenetic relationships between Cottoidei and Notothenioidei, together with their life style, seem to be the main factor driving the globin-sequence evolution.

Evaluation of postoperative toric intraocular lens alignment with anterior segment optical coherence tomography.

We describe the use of a simple tool to evaluate the postoperative alignment of toric intraocular lenses (IOLs). The entire anterior segment is scanned using anterior segment optical coherence tomography and analyzed with an internal dedicated tool. A topographic map is displayed along with an anterior segment image, including a linear axis marker centered on the corneal apex. The marker can be rotated until it is aligned with the line connecting the IOL marking dots, precisely reproducing the IOL astigmatic axis, which is measured in angle degrees. The value of the IOL astigmatic axis is compared with the value of the astigmatic axis shown in real time on the same screen in the topographic map. Evaluating the alignment of a toric IOL axis simultaneously with the topographic astigmatic axis eliminates the potential errors that result from head tilting and strictly correlates with the astigmatic correction achieved.